Bidirectional ferrite phase shifter utilizing nonreciprocal phase shifting means



United States Patent 5,37 Int. Cl. H03h 7/20; H01p /14 US. Cl. 333--31 1 Claim ABSTRACT OF THE DISCLOSURE A bidirectional phase shift arrangement comprising a nonreciprocal ferrite phase shift element located within a waveguide and two three-channel circulators, whose directions of circulation are mutually opposite at the ends of the waveguide.

The present invention relates to electronically controlled phase shifters which make it possible to produce simultaneous phase shifts of identical absolute magnitudes and opposite signs, in two electromagnetic Waves propagating through the phase shifter in opposite directions.

A phase shifter of this sort is of particular interest in electronic-scanning antenna systems, because it al ows a reduction of 50% in the number of phase shifters required.

It is an object of the invention, to provide a phase shifter of this kind in a way which requires the least possible modification of the elements used in such antenna systems.

According to the invention there is provided an electronically controlled two-direction phase shifter arrangement for phase shifting two electromagnetic waves propagating therethrough in opposite directions by phase shifts of identical magnitudes and opposite signs, said arrangement comprising: a wave guide portion having respective ends, controllable nonreciprocal phase shifting means within said guide portion, and two three-channel circu lators, having opposite directions of circulation and having respectively a first, a second and a third channel, the second channel following immediately the first channel in the circulation direction, said first channels being respective input channels for said waves and said second channels being coupled respectively to said ends.

For a better understanding of the invention and to show how the same may be carried into effect reference will be made to the drawing accompanying the following description, and in which:

FIG. 1 is a block diagram of a phase shifter according to the invention, and

FIGS. 2, 3 and 4 illustrate details of the phase shifter in accordance with FIG. 1.

The bidirectional phase shifter shown in FIG. 1 essentially comprises a nonreciprocal ferrite phase shifter element 1, placed within a rectangular waveguide 11, and two three-channel (ABC and A'BC' respectively) ferrite circulators 21 and 22, whose directions of circulation are opposite, as indicated by the arrows.

3,500,261 Patented Mar. 10, 1970 The ferrite component of the phase shifter element 1 is diagrammatically illustrated at 12 and its phase shift control device at 13.

The channels A and A are the inputs of the phase shifter system according to the invention and are coupled to the opposite ends of the waveguide 11 through the channels B and B respectively. The signals applied to the channels A and A appear at the outputs of channels C and C respectively; it is a known property of circulators that the input wave applied to one of its terminals propagates only to the next terminal in the direction of circulation. For example, the wave entering at A appears at B, i.e. enters the phase shifter element 1, whereas the wave entering at B and arriving from B, will be propagated to C. The same holds true for the other circulator.

The phase shifter 1, being of the non-reciprocal type, the additional phase shifts, due to this phase shifter, from A towards C and from A towards C, for all the states of the element 1, will be oppositely directed.

The phase shift element 1 can be designed in any known fashion. It is for example, as shown in FIGS. 2 and 3, of the quantized type, which is based on the remanence properties of the ferrite. As shown in FIG. 2, it incorporates ferrite or garnet tubes 6.1, 6.2 through which the axial conductors, respectively associated with pulse generators 10.1, 10.2, etc., extend. The number of these elementary devices depends upon the elementary phase shift and the total phase shift required.

For the sake of clarity, only two quantized phase shifters have been shown in FIG. 2. Of course, all the elementary phase shifters 10.1 may be controlled together.

FIGS. 3 and 4 show in section, embodiments of the element 6. It comprises a control wire 8, extending through the ferrite and a dielectric filler 7.

Of course, arrangements with an external magnetic field could also be used.

As in the case of unidirectional phase shift elements, if the variations in the control pulse level are sufficiently precise, the intermediate remanence states of a single ferrite element can be used in order to achieve the required range of phase shift variation.

The insertion phase shifts have been so far disregarded. They may differ for the two directions of propagation. They are in fact constant factors and their difference can easily be compensated for, in accordance with known techniques; for example by using waveguides or lines of different lengths for the connections to the two channels.

If the inputs A and A are supplied from a single source G, it is possible with appropriately regulated insertion phase shifts in the two channels, to obtain at C and C phase shifts of p and e, the phase of G being taken as the origin.

The importance of the arrangements according to the invention, for electronic-scanning antennas, will be readily understood. While having all the advantages of the nonreciprocal ferrite phase shifters, they enable the total number of such elements required in the manufacture of the antenna, to be halved.

Of course, the invention is not limited to the embodiments described, which have been given merely by Way of examples.

What is claimed is:

1. An electronically controlled two-direction phase shifter arrangement for phase shifting two electromag- 3 4 netic waves propagating therethrough in opposite direc- Referen e Ci d tions by phase shifts of identical magnitudes and opposite signs, said arrangement comprising: a wave guide portion UNITED STATES PATENTS having respective ends, controllable nonreciprocal phase 2,318,501 1 1 7 Stavis 333-1.l X 3,277,401 10/1966 Stern 1 33324.1

shifting means Within said guide portion, and two threechannel circulators, having opposite directions of circulation and having respectively a first, a second and a third HERMAN KARL SAALBACH, Pflmary Examlnef channel, the second channel following immediately the L GENSLER Assistant Examiner first channel in the circulation direction, said first channels being respective input channels for said waves and said U s C1 X R second channels being coupled respectively to said ends. 10 333 1, 24 1 

